JPS6349086Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a motor actuator used mainly to move an air mix door, an inside/outside air switching door, and other doors of an automobile air conditioner.

As a conventional example, Utility Model Application Publication No. 56-87651 can be cited, and similar conventional examples are shown in Figs. 1 and 2.
As shown in the figure. A conventional example of this type of motor actuator is shown, in which a motor 2 and a gear device 4 are housed in a case 1, and the rotational force of the motor 2 is transmitted to an output shaft 3 via the gear device 4. It is configured to output as follows. The output shaft 3 is fixed to the output gear 27 of the gear device 4, and its rotational position is detected by a position detection device 5 provided between the output gear 27 and the case 1. Based on this, the motor 2 is controlled on and off to give the output shaft 3 a desired angle.

However, the gear device 4 is composed of three gears: a worm 10 fixed to the motor 2, an intermediate gear 12 that meshes with the worm 10, and an output gear 27 that meshes with the intermediate gear 12. Since a predetermined reduction ratio and torque are obtained by the gears 27 and 27, the diameter of the output gear 27 becomes considerably large, resulting in a drawback that the volume of the entire motor actuator also becomes large.

Therefore, the object of this invention is to provide a small-sized motor actuator by employing a new mechanism to eliminate the drawbacks caused by using an output gear in a gear device as described above.

The gist is that at least a motor, a gear device that decelerates the rotation of the motor and transmits it to the output shaft, and a position detection device that detects the position of the output shaft are housed in a motor actuator case. The gear device is composed of a worm fixed to the rotational force of a motor, and a cylindrical intermediate gear having a worm wheel portion on the outer periphery in which the worm engages, and the intermediate gear is rotatable and has a longitudinal direction. The intermediate gear is supported by the case so as to be prevented from moving, and the intermediate gear and the output shaft are connected by meshing a female screw portion formed on the inner surface of the intermediate gear with a male screw portion formed on the outer peripheral surface of the output shaft. The output shaft is slidable in the case and has a rotation stopper that is supported to prevent rotation, and is further provided with a position detection gear that meshes with the male threaded part of the output shaft, and the position detection gear is connected to the case. The reason is that the position detection device is provided in between.

Therefore, the rotation of the intermediate gear is decelerated through the female threaded portion of the intermediate gear and the male threaded portion of the output shaft and directly converted into linear motion of the output shaft, eliminating the need for a large diameter output gear as described above. , it is possible to achieve the above problems.

Examples of this invention will be described below with reference to the drawings.

3 and 4, the motor actuator of this invention is shown, and the case 1 is the upper case 1.
a and the lower case 1b are fixed with adhesive,
Inside this case 1 is a motor 2 and a gear device 4 that decelerates and transmits the rotational force of this motor 2 to an output shaft 3.
and a position detection device 5 for detecting the position of the output shaft 3 are housed.

The motor 2 has both upper ends connected to the motor support parts 6a, 6a of the upper case 1a, and both lower ends connected to the lower case 1b.
The motor support portions 6b, 6b of the motor support portions 6a, 6b abut and are supported in a pinched manner, respectively. Electrode terminals 7a and 7b of this motor 2 are inserted and connected to motor terminals 9a and 9b provided on a wiring board 8 on the lower case 1b.

As shown in FIG. 5, the gear device 4 includes a worm 10 fixed to the rotating shaft 2a of the motor 2, and a cylindrical intermediate gear 12 having a worm wheel portion 11 on the outer periphery in which the worm 10 meshes. It is composed of. The intermediate gear 12 is rotatable and is supported via bearings 30, 30 by intermediate gear supports 13, 13, which are integrally provided with the lower case 1b on both sides in the longitudinal direction, and are prevented from moving in the longitudinal direction. There is. Further, a female threaded portion 14 is formed on the inner surface of the intermediate gear 12 in the longitudinal direction, and a male threaded portion 15 formed on the outer peripheral surface of the output shaft 3 is engaged with the female threaded portion 14.
2 and the output shaft 3 are connected.

Both ends of the output shaft 3 protrude outward from holes 16, 16 formed in the upper case 1a, and a rotation stopper 17 is provided at one end. The other end of the rotation stopper 17 is a rotation stopper insertion hole 18 formed in the upper case 1a.
The output shaft 3 is inserted into the case 1 and is slidably supported by the case 1 to prevent the output shaft 3 from rotating.

Note that there is also a rotation prevention part insertion hole 1 on the other surface of the upper case 1a opposite to the rotation prevention part insertion hole 18.
8' is formed, and this rotation stopper insertion hole 18' is closed with a blind plug 29, and the output shaft is inserted by removing the blind plug 29 and inserting the rotation stopper 17 into the rotation stopper insertion hole 18'. 3 can be installed in the opposite direction.

A position detection gear 19 is engaged with the male threaded portion 15 of the output shaft 3.
9 has a support shaft 20 at the center of the upper and lower surfaces, and this support shaft 20 is supported by the case 1 by being inserted into shaft support holes 21a and 21b formed opposite to the upper and lower cases 1a and 1b. .

As shown in FIG. 6, the position detection device 5 is provided between the position detection gear 19 and the lower case 1b, and the position detection device 5 is connected to the support shaft of the position detection gear 19. It has a disk-shaped contact fixing plate 22 fixed to the contact fixing plate 20 . The contact fixing plate 22 is provided with two contacts 23, 23 having different diameters in the radial direction and projecting downward.
These two contacts 23, 23 are in contact with a conductive plate 24 and a resistive plate 25, respectively, which are fixed to the wiring board 8.

The conductive plate 24 and the resistive plate 25 have a concentric arc shape, and the circumferential angle thereof reaches approximately 250 degrees.
This position detecting device 5 detects the position of the output shaft 3 by replacing the positions of the contacts 23 and 23 with resistance values, and the motor 2 is turned on and off based on this detected signal.
OFF control is performed to give the output shaft 3 a desired position.

Note that 26 is a connector for external connection.

In the above configuration, when the motor 2 is energized via the external connection connector 26, the motor 2 rotates and its rotational force is transmitted to the intermediate gear 12. Therefore, the output shaft 3 tries to rotate together with the intermediate gear 12 due to the frictional force therebetween, but the rotation is prevented by the rotation stopper 17, so that the rotation is converted into a linear motion in the axial direction. At this time, for example, the intermediate gear 12
When the output shaft 3 rotates once, the output shaft 3 moves by one pitch in the axial direction, so a predetermined reduction ratio and thrust can be obtained. When the output shaft 3 moves linearly as described above, the position detection gear 9 that meshes with the output shaft 3 rotates, so the position of the output shaft 3 is detected by the position detection device 5, and the position of the output shaft 3 is detected based on this detected signal. The motor 2 is controlled ON-OFF so that a desired movement distance of the output shaft 3 can be obtained.

As described above, according to this invention, the conventionally used output gear having a large diameter is not required, so the overall volume of the motor actuator can be reduced and it is also lightweight. Therefore, it is advantageous when used, for example, in an automobile air conditioner where installation space is limited.

In addition, in conventional motor actuators, the contact point of the position detection device is provided on the output gear to which the output shaft is fixed, so the rotation angle of the output shaft is detected at an angle equal to the rotation angle of the output shaft. In contrast, in this invention, the position detection gear is meshed with the output shaft that moves linearly, so the ratio of the position detection angle corresponding to the moving distance of the output shaft can be freely set, and the position detection angle Since the angle can be increased to a maximum of 360 degrees, it also has the effect of improving the stopping accuracy of the motor.

[Brief explanation of the drawing]

A conventional motor actuator is shown in FIGS. 1 and 2, with FIG. 1 being a cross-sectional view thereof, and FIG.
The figure is a longitudinal cross-sectional view, FIGS. 3 to 6 show an embodiment of the invention, FIG. 3 is a cross-sectional view of the motor actuator, and FIG. 4 is a line A-A in FIG.
Line sectional view, Figure 5 is a perspective view of the motor and gear system,
FIG. 6 is a sectional view showing the vicinity of the position detection device. 1... Case, 2... Motor, 3... Output shaft,
4...Gear device, 5...Position detection device, 10...
Worm, 11... Worm wheel section, 12...
...Intermediate gear, 14...Female threaded portion, 15...Male threaded portion, 17... Rotating portion, 19... Position detection gear.

Claims (1)

[Scope of utility model registration request] A motor actuator in which at least a motor, a gear device that decelerates the rotation of the motor and transmits it to an output shaft, and a position detection device that detects the position of the output shaft are housed in a case. A worm fixed to the rotating shaft of the motor,
The worm consists of a cylindrical intermediate gear having a worm wheel portion on its outer periphery that engages with the worm, and this intermediate gear is supported by the case so as to be rotatable and prevented from moving in the longitudinal direction. The intermediate gear and the output shaft are connected by meshing the external threaded part formed on the outer circumferential surface of the output shaft with the internal threaded part formed on the outer surface of the output shaft. It has a stop part,
The motor actuator further comprises a position detection gear that meshes with the male threaded portion of the output shaft, and the position detection device is provided between the position detection gear and the case.